macro_rules! codegen_coercions {
({
type: class,
rust_name: $rust_name:tt,
ruby_name: $ruby_name:tt,
meta: { pub: $pub:tt, reopen: $reopen:tt },
struct: (),
methods: $methods:tt
}) => { ... };
({
type: class,
rust_name: $rust_name:tt,
ruby_name: $ruby_name:tt,
meta: { pub: $pub:tt, reopen: false },
struct: $struct:tt,
methods: $methods:tt
}) => { ... };
}